Method and Apparatus for Authenticating Online Transactions Using a Browser

ABSTRACT

A computer-implemented method for authenticating a user using a service provider server and an authentication server, the user communicating with at least one of the service provider server and the authentication server using a user browser. The method includes requesting, using the user browser, the authenticating with the service provider server. The method also includes authenticating, using the user browser, a secure communication channel with the authentication server. The method also includes receiving, using the user browser, a Next Pre-Authentication Anchor (NPAA) value from the authentication server. The method additionally includes temporarily storing the Next Pre-Authentication Anchor (NPAA) value in a user browser cookie associated with the user browser, wherein the Next Pre-Authentication Anchor (NPAA) value is protected by employing Same Origin Policy (SOP).

PRIORITY CLAIM

This application is a divisional of co-pending application Ser. No.12/641,156, filed Dec. 17, 2009, which claims priority under 35 USC119(e) to an earlier filed provisional patent application entitled“METHOD AND APPARATUS FOR AUTHENTICATING ONLINE TRANSACTIONS USING ABROWSER”, Filed Dec. 19, 2008, Application No. 61/139,527, which isincorporated by reference in its entirety herein.

BACKGROUND OF THE INVENTION

Online transactions, including financial transactions and otherconfidential transactions, have long been employed to allow two partiesto conduct business. In a typical online transaction, the user (such as,for example, a bank customer) uses a client browser on a computer toestablished a session with an application server (such as, for example,the banking server that is operated by the bank) and accomplishes thedesired transaction (such as, for example, transferring money from oneaccount to another account). Since online transactions are oftenconducted via the Internet, which is a global public network of routers,servers, trunks, etc., security is always a paramount concern.

Risks to online transaction security include risks that an unauthorizedthird party may be able to obtain the authentication information (suchas userid and password) and may be able to subsequently conductfraudulent transactions to the detriment of the user. For example, ifonly a userid and password are required to log into a bank from anycomputer, a third party with access the user's userid and password wouldbe able to log in from anywhere and perform any transaction that theuser is able to perform, including for example transferring money to anaccount under control by the unauthorized third party.

The stealing of userid and password may be accomplished by techniquessuch as Trojans (generically referring to client-resident applicationsthat snoop the userid and password as they are typed in by the user andrelay the userid and password to the fraudster). Another techniqueinvolves phishing. In an example phishing scenario, the user may receivean email with a message requesting the user to log into a websitepurported to belong to a merchant with whom the user has previously donebusiness (e.g., XYZ Bank). The email contains a link to be activated bythe user. If the user activates the link that is provided with thephishing email, the user is presented with a website that has asubstantially identical look-and-feel to that of the real website (e.g.,XYZ Bank). However, this website actually belongs to the fraudster.Information entered by the user into the fraudster's website, whichmimics the look-and-feel of the real website, would be recorded and usedto subsequently perpetrate fraud on the user. By way of example, thefraudster may employ the entered userid and password to log into theaccount of the user and perform an unauthorized transfer of money.

Pharming is another type of attack that has been employed to practicefrauds on users. In pharming, the DNS (Domain Name System) table ispoisoned so that when the user types in the URL associated with theservice provider (e.g., “www.xyzbank.com”), that URL would be translatedinto an IP address associated with the attacking pharming website. Theuser is then taken to the attacking pharming website, which may attemptto mimic the service provider website in order to obtain the logincredentials of the users. Once the login credentials are acquired,fraudsters may subsequently use those login credentials to practicefrauds on users, such as to fraudulently withdraw money from the user'sbank account.

The aforementioned touches only on some broad categories of onlinetransaction risks. There are other risks currently existing and they arewell known and will not be belabored here. Further, techniques arecontinually developed to combat online fraud. In response, thefraudsters continually develop techniques to defeat the newlyimplemented security measures, including authentication schemes.

One method of combating frauds such as Trojans, phishing, or pharminginvolves using second factor authentication, wherein additionalinformation is required for authentication. With the userid/passwordacting as the first authenticating factor, the application server (e.g.,the bank application), also requires additional authentication based onhardware that is possessed by the device being used for access or by theuser. For example, a hardware token or ATM card may be required for thesecond factor authentication.

However, hardware second factor authentication is both expensive toimplement for the service provider and cumbersome for the user.

In view of the transaction risks that are currently existing and/or thatare being developed in response to security measures, improvedauthentication techniques are desired.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 shows, in accordance with an embodiment of the invention, asimplified network topology including a service consumer browser,representing the browser through which a service consumer (such as abank customer, for example) may access the services offered by a serviceprovider server associated with the service provider (such as the bank,for example).

FIG. 2 shows, in accordance with an embodiment of the invention, thetopology representation of FIG. 1 in greater detail.

FIG. 3 shows, in accordance with an embodiment of the invention, thesteps involved in registration, i.e., setting up a new service consumeror an existing service consumer on a new computer for subsequentauthentication during runtime.

FIG. 4 shows, in accordance with an embodiment of the present invention,the steps for authenticating a service consumer.

FIG. 5 shows, in accordance with embodiments of the invention, thepost-authentication steps.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will now be described in detail with reference toa few embodiments thereof as illustrated in the accompanying drawings.In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itwill be apparent, however, to one skilled in the art, that the presentinvention may be practiced without some or all of these specificdetails. In other instances, well known process steps and/or structureshave not been described in detail in order to not unnecessarily obscurethe present invention.

Various embodiments are described herein below, including methods andtechniques. It should be kept in mind that the invention might alsocover articles of manufacture that includes a computer readable mediumon which computer-readable instructions for carrying out embodiments ofthe inventive technique are stored. The computer readable medium mayinclude, for example, semiconductor, magnetic, opto-magnetic, optical,or other forms of computer readable medium for storing computer readablecode. Further, the invention may also cover apparatuses for practicingembodiments of the invention. Such apparatus may include circuits,dedicated and/or programmable, to carry out tasks pertaining toembodiments of the invention. Examples of such apparatus include ageneral-purpose computer and/or a dedicated computing device whenappropriately programmed and may include a combination of acomputer/computing device and dedicated/programmable circuits adaptedfor the various tasks pertaining to embodiments of the invention.

Embodiments of the invention pertain to techniques for employing thebrowser, and more particularly cookies in browsers, to exchange, storeand generate second authentication factors (which may be used forauthentication in addition to first authentication factor such as useridand password). By using the service consumer browser to serve as ananchor to generate second factor credentials, no cumbersome or expensivehardware solutions are required. Embodiments of the invention employ theSame Origin Policy (SOP) nature of browser cookies to implement aspectsof the inventive authentication to prove authenticity of the serviceconsumer and the device with which the service consumer employs toaccess the services offered by the service provider server.

To elaborate. SOP specifies that a cookie may have attributes thatcouple or associate that cookie with a particular domain name. Thus, acookie associated with a server having the domain name www.example1.comwill not be accessible by another server having a different domain namefor example. Embodiments of the invention improves upon the use of SOPto protect the authentication data values in cookies.

To combat pharming risks, certain required authentication value(s) areassociated with the IP address of the service provider server instead ofwith the URL of the service provider server. In this manner, onlyservers with the same IP address as the service provider server mayaccess the required authentication value(s). Thus, even if the serviceconsumer is directed to an attacking pharming website, authenticationwould fail since the attacking pharming website does not have the sameIP address as the service provider server.

Also, to combat phishing risks, a secure identifier (referred to hereinas an “activation code”) is utilized during a one-time user setup of theservice consumer for authentication. An activation code is arandomly-generated identifier (e.g., numbers, alpha-numeric strings,etc.). An activation code can have added any sort of digital signaturesand tests to distinguish human users from “computers” or “computerprograms”. One skilled in the art will appreciate that even though adigital signature has not been described in detail below, the usage ofthis technique as well as combining the technique with other techniquesfor data obfuscation falls within the scope of the present invention.

Furthermore, embodiments of the invention employ a challenge-responseparadigm to establish a shared secret between the service consumerbrowser and the authentication server. The shared secret enables theestablishment of a secure channel between the service consumer browserand the authentication server. Using the challenge-response paradigm andshared secret stored in the SOP-protected cookie, embodiments of theinvention enable a browser to store, generate, and transmit credentialsfor the purpose of authentication.

FIG. 1 shows, in accordance with an embodiment of the invention, asimplified network topology including a service consumer browser 102,representing the browser through which a service consumer (such as abank customer, for example) may access the services offered by a serviceprovider server 104 associated with the service provider (such as thebank, for example). Network 106 represents the computer network (such asthe internet, for example) that interconnects the computer executingservice consumer browser 102 with service provider server 104. In theexamples herein, it is assumed that network 106 is an untrusted publicnetwork and vulnerable to exploits by attackers (such as attacker 108).

To ensure that the service consumer (e.g., bank customer) is properlyauthenticated before allowing transactions to proceed between theservice consumer and the service provider (e.g., bank), anauthentication server 110 is employed. Authentication is accomplished byfirst performing a one-time user setup of the service consumer forauthentication. The one-time user setup provisions a cookie or cookiesin the service consumer browser with specific values for authenticationpurposes and associates a specific consumer/specific computer with aspecific authentication profile in the authentication server. The setupprocess will be discussed in greater detail later herein in connectionwith FIG. 3.

Once the one-time user setup is completed, authentication may beperformed by authentication server 110 for each session between theservice consumer browser 102 and the service provider server 104. Thevalues setup in the cookie in service consumer browser 102 and thevalues setup for the specific user/specific computer profile inauthentication server 110 during the one-time user setup facilitate theauthentication process during run time (i.e., when the consumer accessesthe service provider server to attempt to conduct a transaction with theservice provider, and authentication is performed prior to thetransaction occurring). Generally speaking, authentication involvespre-authentication, mutual authentication, and post-authenticationsub-processes. The authentication process, including the threeaforementioned sub-processes, will be discussed in greater detail laterherein in connection with FIGS. 4-5.

FIG. 2 shows, in accordance with an embodiment of the invention, thetopology representation of FIG. 1 in greater detail. In FIG. 2, serviceconsumer browser 102, network 106, service provider server 104, andauthentication server 110 are again shown. Within service consumerbrowser 102, there is shown a cookie 202 for storingauthentication-related data of the type that facilitates authenticationby authentication server 110 prior to permitting access by serviceconsumer browser 102 to the services provided by service provider server104.

Cookie 202 includes at least three values: a Next Pre-AuthenticationAnchor (NPAA) value 204, a Server Fingerprint (SPF) 206, and a ClientFingerprint (CFP) 208. NPAA is advantageously associated with and the IPaddress of service provider server 104 and thus accessible only by aserver having the IP address of the service provider server 104 (whichIP address is made known to service customer browser 102 during theaforementioned one-time setup). One skilled in the art will recognizethat by associating the NPAA with the IP address of the service providerserver instead of with the domain name of the service provider server,it is not possible for another server (such as an attacking server thatconnects to service client browser 102 via pharming) to access thecontent of the NPAA. Thus, even if DNS poisoning occurs and customerservice browser 102 is directed by a DNS server to an attacker serverother than the intended service provider server 104, authentication withthis attacker server is not possible due to the fact that the attackerserver will have a different IP address and thus will not be able toaccess cookie 202 and more particularly the NPAA value 204 of cookie202. NPAA value 204 of cookie 202 is encrypted by a key known only toauthentication server 110.

Server Fingerprint (SFP) 206 is associated with the FQDN (FullyQualified Domain Name) of service provider server 104. CFP (ClientFingerprint) 208 is also associated with the FQDN (Fully QualifiedDomain Name) of service provider server 104. CFP 208 is encrypted withthe Rolling Key (RK).

Authentication server 110 includes at least four values forauthenticating, during runtime, with the specific user/specific usercomputer combination that is involved during the one-time setup. Inother words, values stored in these four fields in the authenticationserver 110 will, upon authentication success, allows only the specificuser/specific user computer combination that is involved during theone-time setup to access the services offered by service provider server104.

As can be seen in FIG. 2, authentication server 110 includes aPre-Authentication Anchor (PAA) value 216, a Client Fingerprint (CFP)218, a Server Fingerprint (SFP) 220, and a Rolling Key Challenge (RKC)222. Generally speaking, the PAA 216 is encrypted with the same keyemployed to encrypt NPAA 204. On the other hand, CFP 218, SFP 220, andRKC 222 are encrypted with a system-generated key for the specificuser/specific user computer combination. The generation and provisioningof these values (i.e., PAA 216, CFP 218, SFP 220, and RKC 222) duringthe one-time setup process and during run-time authentication will bediscussed later herein in connection with FIGS. 3, 4, and 5.

FIG. 3 shows, in accordance with an embodiment of the invention, thesteps involved in registration, i.e., setting up a new service consumeror an existing service consumer on a new computer for subsequentauthentication during runtime. During registration, certain values arestored in the secure cookie of the service consumer browser and in theauthentication server for the particular user/device. Further, theshared secret is transferred from the authentication server to theservice consumer browser and the client fingerprint (CFP) is transferredfrom the service consumer browser to the authentication server duringregistration.

In step 302, a request for protection is indicated by the serviceconsumer's browser. Generally speaking, the request for protection isindicated when the service consumer attempts to access services providedby the service provider server and the service provider server and/orauthentication server cannot authenticate the user or specificuser/specific computer combination as having been set up previously forauthentication.

In step 304, service provider server obtains the identity profile forthe new authentication set-up requestor from the service consumer andprovides the identity profile to the authentication server.

In step 306, the authentication server generates PAA (Pre-AuthenticationAnchor) 216 for the specific user/specific computer (which may beidentified by userid and client browser IP address or any other uniqueidentifier for the specific user and the specific computer making therequest, for example). In an example, PAA 216 is generated from theunique customer ID, a time stamp and a random seed number. In step 308,the authentication server generates SFP (Server Fingerprint) 220 for thespecific user/specific computer. In an example, SFP 220 is generatedfrom the unique customer ID, a time stamp and a random seed number.

In step 310, redirect the service consumer browser 102 to the IP addressof the service provider server 104. In step 312, associate the PAA withthe IP address of the service provider server 104. In step 314, redirectthe service consumer browser 102 to the FQDN of the service providerserver 104. In step 316, associate the server fingerprint (SFP) with theFQDN of the service provider server 104.

In step 318, authentication server 110 generates an activation code,which is transmitted (320) to the service consumer himself using anout-of-band communication channel. For example, the activation code maybe sent via an email, a SMS, a private message, an instant message, or aphone call. Out-of-band activation code transmission substantiallyreduces the risk of fraud.

In step 322, the service provider server responds to the setup requestfrom the service consumer browser with an activation webpage to enablethe service consumer to enter the received out-of-band activation code.

In step 324, the service consumer responds to the webpage that requeststhe activation code with the activation code that was receivedout-of-band. The activation code will be employed by the serviceconsumer browser to verify the SFP.

In step 326, a secure channel is set up between service consumer browser102 and service provider server 104. Generally speaking, the securechannel is an encrypted channel that is encrypted using achallenge-response paradigm. In an embodiment, service consumer browser102 generates a challenge seed from, for example, a random number. Usingthis randomly generated challenge seed, service consumer browser 102then encodes the key based on the SFP. The encoded key is then employedto encrypt data to be transmitted to service provider server 104. Thedata to be encrypted and transmitted may include, for example, a knownfact. The challenge itself may be in plain text. Service provider server104 may then generate a response to the challenge. The response isemployed to decrypt the received packets to obtain the known fact. Theknown fact may then be compared against what is known by theauthentication server. If the known facts match, a secure channel isdeemed setup and future communication and encryption may proceed in thesame manner.

In step 328, service consumer browser 102 generates the clientfingerprint (CFP) from, for example, a random number seed. This CFP isthen transmitted (330) to the service provider server 104 via the securechannel. The CFP is then provided from the service provider server 104to authentication server 110, which stores the CFP (332). Authenticationserver 110 then sends (332) a rolling key challenge (RKC) to serviceconsumer browser 102 via the secure channel. Service consumer browser102 receives (step 334) the rolling key challenge (RKC) and derives therolling key (RK) from the RKC (step 336).

In step 338, the CFP in the cookie of service consumer browser 102 isencrypted with the rolling key derived in step 336. At this point, theservice consumer browser 102 is considered setup and protected (340).

FIG. 4 shows, in accordance with an embodiment of the present invention,the steps for authenticating a service consumer. The steps of FIG. 4 areperformed during run time each time authentication is required (such asbefore the start of a session between the service consumer and theservice provider). In contrast, the steps of FIG. 3 are performed onlyonce for each new service consumer or each time an existing serviceconsumer employs a new computer to access the service provider website.

Generally speaking, steps 404-408 relate to pre-authentication. Steps410-438 relate to mutual authentication. Steps 502-512 of FIG. 5 relateto post-authentication.

In step 404, the service consumer browser 102 requests authenticationwith the service provider. The request may be implicit as part ofaccessing the service provider server, for example.

In step 406, redirect service consumer browser 102 to the IP address ofservice provider 104. The purpose of the redirect is to provide the IPaddress of the service provider server 104 to service consumer browser102 and authentication server 110.

Note that the IP address of the service provider server is obtainedsession-by-session. In other words, the IP address of the serviceprovider server is not statically obtained during the one-time setupprocess and stored as a fixed value in the cookie. In this manner, evenif the server moves in between sessions and the service provider servernow has a different IP address, authentication is still possible asdiscussed hereinbelow.

In step 408, authentication server 110 authenticates the PAA receivedfrom service consumer browser 102.

In step 410, the service consumer browser 102 obtains the currentrolling key challenge (RKC) from the authentication server. In step 412,redirect service consumer browser 102 to FQDN of service provider server104.

In step 414, service consumer browser 102 derives the rolling key fromthe rolling key challenge received in step 410 and from the serverfingerprint (SFP). The rolling key (RK) derived in step 414 is employedto decrypt the client fingerprint (CFP) (step 416). Also in step 416,the decrypted CFP is associated with the fully qualified domain name(FQDN) of the service provider server to render this CFP accessible onlyto the server having the FQDN of the service provider server (e.g.,www.abcbank.com).

In step 418, service consumer browser 102 sets up a secure communicationchannel with authentication server 110 using the secure communicationchannel setup technique discussed earlier. In step 420, authenticationserver 110 authenticates the secure channel. In step 422, authenticationserver 110 in turn sets up a secure channel with service consumerbrowser 102 (via service provider server). In step 424, service consumerbrowser 102 authenticates the secure channel.

In step 426, authentication server 110 generates NPAA and sends viasecure channel to service consumer browser 102. This nextpre-authentication anchor (NPAA) represents the pre-authenticationanchor (PAA) employed in the next communication session by the serviceconsumer browser 102. In this manner, the pre-authentication anchorchanges with every session to render it more difficult for a third partyto sign in without having the correct PAA, which changes with everysession.

In step 428, the NPAA is temporarily stored in the service consumerbrowser's temporary memory.

In step 430, redirect service consumer browser 102 to IP address ofservice provider server 104. This redirect allows the service consumerbrowser to obtain the IP address of the service provider server.

In step 432, the service consumer browser gets the NPAA from thebrowser's temporary memory and sets the NPAA value to the IP address ofthe service provider server, thereby rendering the NPAA accessible onlyto the website having the IP address of the service provider server. Inthis manner, even if a pharming attack is attempted, authenticationwould fail since the PAA in the new session would not be accessible bythe attacking pharming website. Note that at no time is the cookie thathas the NPAA associated with the IP address of the service providerserver exposed to or transmitted on the network. Further, the serviceprovider server is expressly configured to not request the serviceconsumer browser to forward the cookie that associates the NPAA with theIP address of the service provider server.

In step 434, redirect service consumer browser 102 to FQDN of serviceprovider server 104. As can be appreciated from the foregoing, the NPAAis furnished to the service consumer browser without exposing the cookiethat associates the NPAA with the IP address of the service providerserver to the network.

Once both service consumer browser 102 and authentication server 110authenticate, mutual authentication is deemed completed (436).

FIG. 5 shows, in accordance with embodiments of the invention, thepost-authentication steps. In step 502, the mutual authenticationchannel is assumed to have been established from the mutualauthentication stage. In step 504, the authentication server 110generated the rolling key challenge (RKC). In step 506, the rolling keychallenge is sent via the secure communication channel to serviceconsumer browser 102. In step 508, service consumer browser 102 decodesthe rolling key (RK) using the received RKC and the server fingerprint(SFP). In step 510, service consumer browser 102 encrypts the clientfingerprint (CFP) with the decoded rolling key (RK). In this manner, theclient fingerprint (CFP) is encoded with a different rolling key eachsession. In step 512, the encrypted CFP is saved to the secure cookieand is associated with the FQDN of the service provider server.

While this invention has been described in terms of several preferredembodiments, there are alterations, permutations, and equivalents, whichfall within the scope of this invention. It should also be noted thatthere are many alternative ways of implementing the methods andapparatuses of the present invention. Although various examples areprovided herein, it is intended that these examples be illustrative andnot limiting with respect to the invention.

1. A computer-implemented method for authenticating a user using aservice provider server and an authentication server, said usercommunicating with at least one of said service provider server and saidauthentication server using a user browser, comprising: receiving, usingsaid service provider server, a request for said authenticating fromsaid user; providing, using said service provider server, a first IPaddress associated with said service provider server, from said serviceprovider server to said user and said authentication server; andredirecting said user browser to said first IP address associated withsaid service provider server.
 2. The method of claim 1 wherein saidfirst IP address associated with said service provider server isobtained session-by-session.
 3. The method of claim 1 further comprisingredirecting said user browser to Fully Qualified Domain Name (FQDN) ofsaid service provider server.
 4. The method of claim 3 wherein saidFully Qualified Domain Name (FQDN) of said service provider server isassociated with a decrypted Client Fingerprint (CFP).
 5. The method ofclaim 1 wherein said service provider server is configured to notrequest said user browser to forward a user browser cookie whichassociates a Next Pre-Authentication Anchor (NPAA) value with said firstIP address of said service provider server.